Process for conditioning a hard snow or ice-like snow covered ski slope and apparatus therefor



3,463,548 -LIKE Aug. 26, 1969 J. w. KELLY PROCESS FOR CONDITIONING A HARD SNOW OR IGE SNOW COVERED SKI SLOPE AND APPARATUS THEREFOR Filed April 5, 1967 E i S W R 1 0 s A W J L w,

United States Patent PROCESS FOR CONDITIONING A HARD SNOW 0R ICE-LIKE SNOW COVERED SKI SLOPE AND APPARATUS THEREFOR James W. Kelly, 509 Pecks Road, Pittsfield, Mass. 01201 Filed Apr. 3, 1967, Ser. No. 627,783 Int. Cl. Elllc 19/26 US. Cl. 299 16 Claims ABSTRACT OF THE DISCLOSURE Apparatus and process for conditioning a hard snow or ice-like surface employed in combination a frame carrying a rapidly rotatable pulverizing member. This member has fracturing means projecting outwardly from an elongated body. Means for bringing and holding said member into engagement with the surface so that a portion of the periphery of said body is below the level of the surface to be conditioned. Means for moving said apparatus over said surface. Power means for rotating themember at high speed with respectto the translational motion of the apparatus.

BACKGROUND on THE INVENTION This invention pertains to an apparatus for conditioning a hard snow or ice-like snow covered ski slope and a process therefor and more particularly to an apparatus and process which provides for mechanically pulverizing such a surface to a thick layer of powdered snow.

To the ski resort owner two conditions means irrecoverable loss of business. One is a lack of snow on the slopes and the other is unskiable hard snow or ice-like-snow on the slopes. If the temperature is low enough, the first condition can, to some extent,be overcome' by the use of snow making apparatus. The second condition, however, has never been successfully coped with. In the latter case, the surface is ina dangerous, unskiable condition because of the hard snow and/or ice, and even meister skiers cannot get an edge on'the hard surface. The surface has aptly been described as boiler plate" by resort operators.

Consequently, ski resort operators, particularly those of the northeastern United States where icing and glazing conditions too often prevail, have tried every known device, implement and technique in a vain attempt to economically convert an unskiable surface to a skiable surface.

Among the devices employed without commercial success were rakes, scarifiers, spike and disc harrows, chain drags, and other farm implements. These devices at best provide shallow, slow, ineffectual breakage of the surface. Chemical means, such as the use of calcium chloride, were also tried without success. One operator even tried a flame thrower, without success; and the attempt only served to emphasize the desperateness of the situation.

As a result, when a hard snow or ice-like condition exists, resort operators have come to rely upon the use of equipment designed to artificially create snow. This is a tremendously expensive compromise. The snow guns, the piping, the labor, the power, etc., are costly and the result usually is a few inches of snow on a still slick undersurface on only one or two slopes.

Without more, it is clear that a need has existed since the beginning of commercial skiing, for a device or process which will convert the surface of a hard snow and/ or ice covered ski slope into a powdery snow surface. With such a device or process, 25-30 no skiing days each season, where the slopes, the ski lifts, the supporting facilities, etc.,

3,463,548 Patented Aug. 26, 1969 are just one grand unproductive overhead, would be returned to 25-30 all lifts in operation days.

It is an object of this invention to provide an apparatus for conditioning hard snow or ice-like snow surfaces, particularly ski slopes.

It is another object of this invention to provide an apparatus having a pulverizing means which rapidly powder large expanses of hard snow surfaces.

It is a further object of this invention to provide a surface conditioning apparatus having an elongated snow and ice-crushing body having a plurality of fracturing appendages, said body and apparatus capable of being rotated at high speeds with simultaneous movement across the hard snow or ice-like surface.

It is still a further object of this invention to provide an economical and effective method of conditioning a hard snow surface.

SUMMARY OF THE INVENTION The invention is concerned with an apparatus for conditioning a hard snow or ice-like surface comprising in combination a frame carrying at least one rotatable pulverizing member, power means for rotating said member and means for moving said apparatus: over said surface while said member is rotating in contact therewith. Said member comprises an elongated body having fracturing means projecting outwardly from said body a distance less than the selected conditioning depth. Said member is adapted for rapid rotational motion with respect to its longitudinal axis with a portion of the periphery of said body below the level of the surface to be conditioned.

In a more limited sense, the fracturing means is a plurality of spaced apart appendages, said appendages having at least one fracturing face thereon disposed at an angle to a plane normal to the longitudinal axis of the body carrying said means. In a preferred embodiment the appendages will project a distance less than the radius of said body. I another limited embodiment, the radius of the body will be approximately equal to the maximum conditioning depth and the appendages will project outwardly a distance substantially less than the radius of said body so that when operating at maximum conditioning depth the longitudinal axis of said body will be close to surface level.

The body is preferably generally circular in cross section and the appendages carried thereby are disposed in a plurality of circumferentially spaced rows.

The invention is also concerned with a method of conditioning a hard snow or ice-like snow covered ski slope. It comprises bringing into contact with such a surface a rapidly rotating pulverizing member. The member comprises an elongated body having fracturing means projecting outwardly from said body a distance less than the selected conditioning depth. The rotating member is lowered so that at least a portion of the periphery of the elongated body is rotating below the level of the surface to be conditioned to form a U-shaped trough in the hard snow. While maintaining the rotating member at this depth, the member is moved in a plane generally parallel to the level of the surface and into one of the exposed hard snow faces of said trough to fracture, crush and pulverize said hard snow. Except in unusual circumstances, the rotating member will be rotating complementary to its horizontal movement. In a limited embodiment, the fractured, pulverized and powdered particles will be directed against an impactdeflection plate to further reduce the size of the particles and to direct the particles to the right or left of the direction of travel.

The apparatus and process of the present invention presents the first commercially acceptable solution to a problem which heretofore has shut down the operation of ski slopes and horse race tracks. By the present invention hard packed snow and ice-like surfaces are converted to fine powder in a remarkably short period of time and by a comparatively simple apparatus which is capable of sustained operation without frequent adjustment or break down.

BRIEF DESCRIPTION OF THE DRAWING FIGURE 1 is a side view in elevation of an apparatus constructed in accordance with the invention;

FIGURE 2 is a view, partly in section, on the line 22 of FIGURE 1;

FIGURE 3 is a partial view of a pulverizing member having a different arrangement of pulverizing faces;

FIGURE 4 is a partial view of another embodiment of the pulverizing member; and

FIGURE 5 is an end view of a still further embodiment of the pulverizing member and it also illustrates the required position of the pulverizing member with respect to the surface to be conditioned.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIGURES 1 and 2 a conditioning unit is shown, having a hard snow or ice-like snow surface engaging main frame 12. The main frame 12 includes a pair of support runners 14 and 16, which are disposed in parallel spaced relationship and extended throughout the length of the apparatus. The runners or skis 14 and 16 are joined at the forward and rearward ends by crossbars 18 and 20. Pivotally mounted on the front of each runner is a coupling member 22 which is adapted to be connected to a tractor or other vehicle unit (not shown) for transverse movement of apparatus 10 in the direction of arrow A.

An auxiliary or subframe 28 is carried on the main frame 12 and supported above it by a pair of upright members 24, at the front of the main frame, and a pair of upright members 26, at the rear of each runner. Subframe 28 is attached to pivot 30 on each rear verticle member 26, and is supported at its leading edge by a vertical adjusting means 32. Subframe 28 also carries a power means 34 and a pulverizing means 36.

The power means 34, which may be any device such as an internal combustion engine, electric or hydraulic motor or the like, is mounted on mounting members 38 above subframe 28. Pulverizing means 36 is carried beneath subframe 28 by means of bearings 40 and 42, and is coupled to power means 34 by a drive means 44 and a transmission-clutch arrangement 46.

Auxiliary frame 28 is a generally rectangular structure having a pair of spaced apart side members 48 and 50 which are positioned above runners 14 and 16. The pulverizing means 36 is journalled by bearings 40 and 42 to each side member so as to be disposed in a generally horizontal position across apparatus 10 and generally transverse to the direction of the travel of apparatus 10.

Vertical adjusting means 32 includes a hydraulic cylinder 52 which is mounted in an upright position on a connecting member between uprights 24. The top portion of cylinder 52 is pivotally connected to a hinged member 54 and through it to subframe 28 by a chain 58 which provides pivotal movement of the subframe 28 at pivot 30.

Hydraulic power is provided to the cylinder for pivoting the subframe by means of a hydraulic pump 60 which is driven and controlled from motor 34.

In this specific embodiment, pulverizing means 36 is an elongated metal cylindrical member 62 approximately 6 feet long and 8 inches in diameter. A plurality of appendages 64 are mutually spaced and longitudinally staggered on the cylinder surface and extend outwardly therefrom. The appendages are disposed in four rows on the cylinder with those of one row longitudinally displaced a distance corresponding to the space between appendages. Each appendage 64 is a suitably thick metal member, such as steel or the like. These extend about one inch from the hollow cylinder and three inches along it, so as to provide pulverizing faces 66 and 68 on both sides of each appendage as shown.

Member 36, including the pulverizing faces, has a total diameter of approximately 10 inches. During operation, employing a depth of cut in the order of three to four inches (see depth e of FIGURE 5), the longitudinal axis of the member will be at, or close to, the ice-like surface 0 so that the force of moving the apparatus across the surface will be primarily directed against the three or four inch unpowdered, exposed hard snow face. This provides an exceptionally high degree of pulverizing efficiency.

The inventive combination uniquely employs, with outstanding advantage, the transverse movement of the rap idly rotating, comparatively small diameter member having stubby snow fracturing faces. This is in contrast to a long-bladed member of large diameter, where the axis will be too far above the surface and its design will cause it to roll or walk over, rather than work at the exposed hard snow face.

Long blades, without the bite limitation of the elongated body, will engage so large a portion of the surface that the member will be excessively loaded and will tend to walk on the hard snow surface. The overall area of each appendage, that is both its length, along the longitudinal axis, and its height (or outer projection) as well as the overall number of appendages, contribute to the load or drag on the rotor. These factors determine the gross amount of snow moved during each revolution. It is believed, however, that the outward projection of the appendages is the largest single loading factor. Hence, while long longitudinal appendages will increase the appendage area and consequently the drag, this drag does not compare to the increased load resulting from a comparable increase in appendage height.

Advantageously, the novel rotor is highly efficient in that it provides an outward projection, or bite, which is small as compared to the pulverizing depth. Stated otherwise, appendages, having limited bite, are disposed in the novel arrangement at a practical distance from a central axis.

This allows a pulverizing depth almost equal to the overall radius of the rotor, and a'tangential velocity of the appendages the same as that of the ends of a long bladed member. Thus, the rotor of the present apparatus does not have the disadvantage of large bite, excessive drag and the walking tendency of along bladed unit.

It should be understood that comparatively narrow fracturing faces (for example inch or less, which approach needle-like appendages) are to be generally avoided. Appendages of this type promote snow clogging of the rotor which results in detrimental imbalance and loss of efficiency of the rapidly rotating rotor. If appendages of this narrow type are spaced far enough apart to avoid clogging then there will be no effective fracturing, merely a scarifying effect.

A further advantage of keeping the overall rotor diameter comparatively small is that it also minimizes drag. This follows from the fact that the snow engaged area at the bottom of the rotor is only slightly greater than that of the exposed snow wall at the fracturing side of the rotor. This is in contrast to a rotor of very large diameter wherein the depth of cut is shallow as compared to rotor diameter and a comparatively large area of snow is engaged at its bottom.

It should also be noted that the pivot point 30 of the rotor bearing sub-frame 28 is rearward of the rotor 36 and slightly above snow level (for example, approximately 10 inches). When the rotor'is lowered into contact with the surface, the resulting force of the transverse movement of apparatus 10 is directed through the rotor, at a small angle to the surface rather than parallel to it. This provides for engagement of the rotor with the surface through an arcuate downward movement of said rotor. This arrangement insures the continued engagement of the rotor with the surfaces and inhibits walking over the surface.

In the embodiment shown, the total weight of apparatus 10, due to a great extent to the weight of the internal combustion engine, is approximately 1500 pounds. In circumstances where the rotor is powered from the lead vehicle (for example by hydraulic means) apparatus would be considerably lightened, consequently the direction of the engaging force and the design of the rotor according to the limitations of the present invention become even more important.

In operation, the pulverizing member 36 is rotated clockwise in the direction of arrow B at high speed, for example 300-2800 r.p.m., and is lowered and forced into engagement with the boiler plate surface so as to form a trough about 1 /2-4 inches in depth. Apparatus 10 is then moved against one of the faces of the trough so that member 36 rapidly and continually fractures, pulverizes, and powders the hard surface. The body or cylinder 62 limits the bite of the appendages allowing it to be rotated at high speed without undue load, even at surface depths about equal to its radius. This follows from the provision of comparatively short pulverizing faces extending from the surface of the cylinder. Moreover, cylinder 62 not only operates to limit the bite, but also, materially contributes to the further and continued pulverization and mastication of the fractured ice-like snow.

The apparatus depicted in FIGURES 1 and 2 was operated over the Shamrock Trail at Brodie Mountain Ski Resort located in New Ashford, Mass. The announced skiing conditions for the day involved at Brodie Mountain was poor with icy spots. This meant, the surface was extremely hard and hazardous. This particular trail was in an unskiable condition.

The apparatus was towed in place by an endless track vehicle. The engine of the apparatus, a Mercedes-Benz, 100 horsepower diesel engine, .was started and run at a shaft speed of approximately 2000 rpm. The rotor was lowered into the hard surface a distance of from 2-2/2 inches. Maintaining the rotor at about this depth or as close thereto as the terrain would allow, the apparatus was pulled forward at a speed averaging from 3-5 miles per hour. The apparatus converted the surface of the ski slope into a soft, well-pulverized powder. The 2-2 /z inches of hard snow was converted to from 5-6 inches of excellent, skiable powder.

The apparatus also was tested under even more severe conditions on a ski slope at Stowe, Vt., and a slope at Sugarbush at Warren, Vt. In each instance the surface was converted from unskiable to excellently skiable.

It is believed that the theory of operation can best be explained by referring to FIGURE 5, while disregarding for the moment optional short appendages 78 as shown therein. For purposes of clarity no pulverized snow particles are shown in the illustration.

A plularity of crushing and grinding frames or chambers d are defined by (1) the surface area of cylinder 82 between adjacent appendages 80, (2) each two opposing faces of adjacent appendages 80, and (3) the hard snow face being worked upon by the rotor. The effective parts of the frames are the face of appendage 80 which fractures off part of the surface 0 (and its undersurface to be conditioned) and the surface area of cylinder 82 in ad Vance of this face. The rotor is in rapid rotation in the direction of arrow B and is being horizontally traversed in the direction of arrow A.

The fracturing faces of appendages 80 will dislodge comparatively large particles of hard snow or ice-like snow and the forward and downward action of the frames will grind and repulverize these particles against the hard snow face being worked upon. As a result an extremely fine powdered snow is thrown rearwardly of the apparatus.

The rotor member shown may be operated in the reverse (counterclockwise) direction, since appendages 64 have faces in both directions. This has some advantage in circumstances where the apparatus must be backed into diflicult areas; however, the pulverization action is not nearly as effective as the clockwise rotation.

Advantageously, the elongated member need not be restricted to cylindrical bite limiting means. For example, other geometrical cross sections approaching a cylinder would be suitable.

Although in the illustrated embodiments, the appendages are welded to the cylindrical surface, the appendages could extend through the cylinder and attach to a central shaft or adjacent appendages could be replaceable wide U-shaped members.

A gang of several rotors may also be employed rather than a single unit shown. Hence, several rotors could be operated in a staggered overlapping arrangement to treat a wide track.

In FIGURE 3 appendages 64 are arranged in two helical rows along a cylinder 72 to provide .a further modification of pulverizing member 36. As in FIGURES 1 and 2, each appendage is illustrated as being disposed parallel to the longitudinal axis; however, various angular positions could be employed. For example, the fracturing faces could be aligned with the helical rows. Of course, the appendages are intended to be placed so that the fracturing face is always at some effective angle to a plane normal to the longitudinal axis. Furthermore, oppositely directed helical rows could also be included to provide crossed helical rows.

In FIGURE 4, thick appendages 74' are illustrated on a cylinder 76 is eight axially aligned rows, rather than the four rows of FIGURES 1 and 2, to illustrate a modification having a different thickness of appendages and row arrangement. The appendage thickness may vary from as little as A inch to 1 inch, or more, since the appendage primarily utilizes its face to fracture and pulverize the surface, rather than its edge to cut as a knife.

Advantageously, appendages of varied height may also be employed, as shown in FIGURE 5. Herein, shorter appendages 78 are interspersed between appendages 80 and are approximately one-half the height of the latter. These shorter appendages serve as repulverizer plates, which extend within the previously described frames or chambers, and provide an obstruction therein which further pulverizes the face-dislodged particles.

Generally, the indicated apparatus is allowed to freely throw the snow rearward of the device, however, further pulverizating or redistributing of the powder can be provided by a baffle means, such as plate 86 shown in FIGURE 1, which is mounted rearwardly of the rotor. The baffle or impact plate may be fixed, so as to be generally perpendicular to the wake of the snow or it may be pivotally mounted at each end to allow a variation in the exposed bafl'le area. The variation can be employed not only to aid pulverization but also to control the distribution of the powdered material. For example,

with maximum plate area exposed to the throw of the rotor, much of the powder will be forcefully thrown at the impact plate; whereas with the plate up, the powder will be thrown approximately ten to thirty feet to the rear. This allows the device to also level and fill the ski slope.

Advantageously, although the rotor is illustrated as generally transverse to the apparatus, it may also be positioncd at an angle so as to throw the created powder to the side of the conditioned track, instead of directly to the rear. Moreover, the rotor may be designed to be swiveled with repect to the transverse position shown. By positioning the rotor at other than 90 to the direction of forward motion, the powder may be thrown to either side of the direction of vehicular motion, and the ski slope leveled and filled as desired.

Other modifications are also possible. The indicated apparatus could be combined with a collector and blower arrangement, positioned behind the rotor. This would collectthe thrown snow in a chute, or the like, and feed it to the blower, for distribution in a reasonable radius around the vehicle.

It will be appreciated that for a ski slope, the depth to be conditioned normally will be from 1 to 6 inches and preferably from about 2 to 4 inches. A depth less than one inch is wasteful of the apparatus, difficult to control and productive of too thin a layer of powder. A depth of more than 6 inches calls for considerable driving power and there is no advantage in pulverizing to this depth. The apparatus of the present invention converts each inch of depth of the hard packed snow to from 2 to 3 inches of powder. Thus, the bulk increase resulting from pulverizing over 6 inches of hard surface would be from 12 to 18 inches. This is far more than is necessary for good skiing conditions.

It follows from this that the preferred practical overall rotor radius (body and appendages) should range from about 1 to 6 inches and the appendage length should be preferably less than the radius of the body.

Other power means are also suitable. For example, unit may be powered and controlled from the front vehicle. In addition, the pulverizing member alone, or the total apparatus may be combined with the lead vehicle to provide transverse motion and pulverizing in one machine. In this modification the vehicle and rotor arrangement should be such that the vehicle does not run over and repack the conditioned surface.

What is claimed is:

1. Apparatus for conditioning a hard snow or ice-like surface into a powdered surface comprising in combination a frame carrying at least one pulverizing member,

surface-contacting means in association with said frame for supporting said apparatus over the surface to be powdered, said pulverizing member comprising an elongated body having a plurality of circumferentially spaced appendages projecting outwardly from said body a distance less than the selected conditioning depth, said appendages disposed on said body so that during operation of said apparatus substantially all of the surface worked upon is appendage-contacted, means for downwardly bringing and holding said member into engagement with the underlying surface so that a portion of the periphery of said body is below both the level of said underlying surface to be conditioned and the level of the surfacecontacting portion of said contacting means, means for moving said apparatus over said surface, and power means for rotating said member at high speed with respect to the translational motion of said apparatus.

2. The apparatus of claim 1 wherein said appendages are longitudinally and circumferentially spaced on said body, a plurality of said appendages being longitudinally offset to assure substantially all of said surface worked upon is appendage-contacted, said member is disposed generally transverse to the direction of travel of said apparatus, and said member is adapted for rotation in a direction complementing said travel and at a speed such that the tangential velocity of said appendages greatly exceeds the rate of travel of said apparatus.

3. An apparatus as claimed in claim 2 wherein said pulverizing member is supported by a su'bframe, and said subframe is pivotally mounted with its pivot point rearward of said member and at a height above the snow surface equal to or slightly exceeding the overall radius of said member to provide for application of the engaging force downwardly at a small angle to the surface.

4. An apparatus as claimed in claim 1 including an impact-deflection plate disposed in spaced parallel relationship to said pulverizing member and in the snow wake, and said plate is pivotally mounted at its extended ends to allow impact and deflection variation.

5. An apparatus as claimed in claim 1 wherein said pulverizing member is adapted to be sWiveled to either side of the direction of travel.

6. The apparatus of claim 1 wherein said appendages project a distance less than the radius of said body.

7. The apparatus of claim 6 wherein said radius is approximately equal to the maximum conditioning depth, and said appendages project outwardly a distance substantially less than said radius so that when operating at maximum conditioning depth the longitudinal axis of said body will be close to thelevel of the surface-contacting portion of said contacting means. A p

8. The apparatus of claim 1 including alternate circumferentially spaced appendages from M1 to the height of appendages of adjacent rows.

9. The apparatus of claim 1 wherein said body is gen erally circular in cross section, and said plurality of appendages include longitudinally spaced appendages dis posed in a plurality of circumferentially spaced rows, said appendages project in a substantially radial direction, said rows are aligned with the longitudinal axis of said body, and the appendages of one row are offset with respect to the appendages of other rows.

10. The apparatus of claim 9'Wherein said appendages project from 0.5-2 inches and are from 2 to 4 times as long as the projected height, and the longitudinal spacing between adjacent appendages is 0.5-1.5 times the appendage length.

11. The apparatus of claim 10 wherein the radius of said body is from 1 to 6 inches.

12. The apparatus of claim 10 wherein the radius of said body is about 4 inches; said appendages are substantially flat members about inch thick, 4 inches long and 1 inch high; said appendages are disposed in four longitudinal rows around said cylinder with each appendage aligned with the longitudinal axis and longitudinally spaced about 3 inches from adjacent appendages of the same row; said appendages extend in a generally radial direction; and the appendages of one row are olfset from those of adjacent rows by an amount equal to their length.

13. A method of conditioning an underlying hard snow or ice-like surface to a powder-like condition comprising positioning above said underlying surface a rapidly rotating pulverizing member, said member comprising an elongated body having fracturing appendages projecting outwardly from said body a distance less than the selected conditioning depth; bringing said rapidly rotating member into contact with said underlying surface; maintaining said rapidly rotating member so that only a portion of said member and at least part of the periphery of the elongated body is below the level of said underlying surface so as to form a trough in said surface, and moving .said member into the exposed hard snow or icelike face of said trough in a plane generally parallel to the level of said underlying surface; the rotational motion of said member being at high speed with respect to its translational motion so as to powder said surface and redistribute the powder on the treated surface.

14. The method of claim 13 wherein said member is rotating at a speed of 300-2800 r.p.m.

15. The method of claim 14 wherein said member is rotating at a speed of about 2000 r.p.m.

16. The method of claim 1 wherein the powdered particles are directed against an impact-deflection plate.

References Cited UNITED STATES PATENTS 721,364 2/ 1903 Green et al. 299-25 2,156,066 4/1939 Royer et al. 299-25 2,223,213 11/ 1940 Kersten 299-2S 2,606,011 8/1952 Lommen 299--25 1,836,116 12/1931 Hayen 37-43 2,024,551 12/ 1935 Thornhill 37-43 2,132,790 10/1938 Jeswine 37-43 ERNEST R. PURSER, Primary Examiner US. Cl. X.R. 37-43; 241-27 *;g;;g UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,463 j48 Dated A g t 26 1969 Inventofld) James W. Ke 11V It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

[ Claim 16, line 1 the numeral "1" should read 13 a SIGNED AND SEALED NOV 2 51969 (SEAL) Attest:

Edward M. Fletcher, Ir IA E 80mm, JR- Auesfing Officer Gonmissioner of Patents 

